The organism Entamoeba histolytica is one of the causes of amoebic dysentery.Infection occurs when cysts of this organism are swallowed and enter the patient's digestive tract.These cysts each have four nuclei,and once in the digestive tract the cysts divide into four cells,each with its own nucleus.Each new cell can invade the mucosal lining of the digestive tract by pushing its pseudopodia into the lining.This organism is a ________ that belongs to ________.